Alert archive / Louisiana / Mesoscale Discussions in 2019

Mesoscale Discussion 2202

December 16, 20194 states

The Storm Prediction Center issued this mesoscale discussion at Dec 16, 2019, 9:43 AM CST for 4 states. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: Dec 16, 2019, 9:43 AM CST (15:43 UTC)
Expired: Dec 16, 2019, 12:15 PM CST
In force: 3 hr
Issued by: the Storm Prediction Center
Chance of a watch: 80%

All 57 counties

Ashley County, AR, Chicot County, AR, Acadia Parish, LA, Allen Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Bienville Parish, LA, Calcasieu Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, De Soto Parish, LA, East Carroll Parish, LA, Evangeline Parish, LA, Franklin Parish, LA, Grant Parish, LA, Jackson Parish, LA, Jefferson Davis Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Rapides Parish, LA, Red River Parish, LA, Richland Parish, LA, Sabine Parish, LA, Saint Landry Parish, LA, Tensas Parish, LA, Union Parish, LA, Vernon Parish, LA, West Carroll Parish, LA, Winn Parish, LA, Adams County, MS, Claiborne County, MS, Copiah County, MS, Franklin County, MS, Hinds County, MS, Humphreys County, MS, Issaquena County, MS, Jefferson County, MS, Leflore County, MS, Sharkey County, MS, Sunflower County, MS, Warren County, MS, Washington County, MS, Wilkinson County, MS, Yazoo County, MS, Hardin County, TX, Jasper County, TX, Newton County, TX, Orange County, TX, Sabine County, TX, San Augustine County, TX, Shelby County, TX, Tyler County, TX

The radar

The Ft Polk radar (KPOE), 89 km from the middle of the area, began a volume at 15:42 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

Tornado Watch 700Dec 16, 10:40 AM CST

The nearest sounding before it

Shreveport, LA (KSHV), launched 12:00Z, 3.7 hours before the alert went out and 146 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 1108 J/kg
Mixed-layer CIN: -81 J/kg
Mixed-layer LCL: 720 m above ground
0-6 km bulk shear: 57 kt
0-1 km storm-relative helicity: 319 m²/s²
0-3 km storm-relative helicity: 322 m²/s²
Significant tornado parameter: 1.4
Supercell composite: 7.4

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Dec 16, 4:24 AM CST	Mesoscale Discussion	SPC	Benton, Carroll	6 hr
Dec 16, 10:02 AM CST	Mesoscale Discussion	SPC	Arkansas, Bradley, Calhoun, Clark, Cleveland, Columbia and 19 more	118 min
Dec 16, 10:40 AM CST	Tornado Watch	SPC	Ashley, Chicot, Union	9 hr
Dec 16, 11:24 AM CST	Mesoscale Discussion	SPC	Allen, Avoyelles, Beauregard, Catahoula, Evangeline, Grant and 3 more	96 min
Dec 16, 1:16 PM CST	Mesoscale Discussion	SPC	Allen, Avoyelles, Catahoula, Concordia, Evangeline, LaSalle and 4 more	89 min
Dec 16, 1:31 PM CST	Mesoscale Discussion	SPC	Beauregard, Bienville, Calcasieu, Grant, Jackson, Lincoln and 8 more	119 min
Dec 16, 1:52 PM CST	Mesoscale Discussion	SPC	Alcorn, Attala, Benton, Calhoun, Carroll, Chickasaw and 22 more	83 min
Dec 16, 2:22 PM CST	Tornado Watch	SPC	Alcorn, Calhoun, Chickasaw, Choctaw, Clarke, Clay and 30 more	8 hr
Dec 16, 3:08 PM CST	Mesoscale Discussion	SPC	Amite, Copiah, Franklin, Jefferson Davis, Lawrence, Lincoln and 3 more	67 min
Dec 16, 3:10 PM CST	Mesoscale Discussion	SPC	Alcorn, Attala, Calhoun, Chickasaw, Choctaw, Clay and 16 more	65 min
Dec 16, 3:47 PM CST	Tornado Watch	SPC	Greene, Perry, Wayne	10 hr
Dec 16, 4:32 PM CST	Mesoscale Discussion	SPC	Covington, Jasper, Jefferson Davis, Jones, Lawrence, Marion and 1 more	88 min
Dec 16, 4:45 PM CST	Mesoscale Discussion	SPC	Itawamba, Monroe, Tishomingo	60 min

Nearby

Mesoscale Discussions in Louisiana, 2019 Mesoscale Discussions in Mississippi, 2019 Mesoscale Discussions in Texas, 2019 Every mesoscale discussion in 2019

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.